Grainger was one of the twentieth century's most extraordinary and contradictory musical figures: Australian-born collector of English and Danish folk song (it was Grainger who collected Brigg Fair), great pianist (he briefly studied with Busoni, and Grieg said that Grainger played his concerto the way he wished he could play it himself), naturalised U.S. citizen, pacifist, army bandsman, flamboyant showman (he and his Swedish wife, Ella, were married on stage at the Hollywood Bowl).

Grainger refused to use Italian musical terms, instead writing for "foursomes" and "fivesomes" and littering his scores with directions such as "louden" and "soften". He also believed implicitly in the superiority of the "Nordic races", yet was fascinated by non-Western music and was the first person to invite an all-black jazz band to a U.S. university for purposes other than entertainment (1932, when he asked the Duke Ellington Band to illustrate a lecture he gave at NYU).

And health fanatic: Grainger was tremendously fit and could reportedly throw a tennis ball over Delius' house in Grez-sur-Loing from the back yard, run through the house and catch it in the front (as memorably dramatised in Ken Russell's A Song of Summer, his docudrama on the final years of Grainger's great friend). There are also stories of his running twenty or more miles to a concert in South Africa in the company of a Zulu tribe whom he had befriended. (And subsequently being unable to understand why his new friends were not welcome inside the concert hall. A mass of contradictions our Percy)

Yet today Grainger is largely associated in the general musical public's mind with a single work, Country Gardens and that heard usually in homogenised and emasculated arrangements by other hands.

In recent years something of a reassessment of Grainger's considerable output has been going on and this new disc represents a part of that process, coupling what is probably his masterpiece, Lincolnshire Posy, with several less well-known, but scarcely inferior works.

Firstly, although the longest work here weighs is at under nineteen minutes, this disc proves triumphantly that Grainger was no miniaturist. His pieces may be short, but they are often scored for huge orchestral forces, particularly tuned percussion. This is certainly true of the final work, The Warriors composed in 1916 from a suggestion by Thomas Beecham for a ballet scene; Beecham promised a scenario but never delivered.

The Warriors is an endlessly energetic work, "an orgy of war-like dances, processions and merry-making, broken, or accompanied, by amorous interludes" the composer called it. Although not based on folk themes, Grainger's compositional footprints are to be found in every bar. More surprising, perhaps, is the work's rhythmic complexity – at times different sections of the orchestra play in different rhythms and tempos – leading to his anticipated requirement for an assistant conductor.

If this has the ring of Charles Ives about it, there is some justice in that, although it is hard to believe that Grainger was familiar with the older man's work. Certainly they share an entirely refreshing eclecticism, catholic tastes and an enthusiasm for experimentation. In addition, while each man cast his net wide in search of thematic material, each has such a strong personality that the author of the music is never in doubt.

The suite In a nutshell was assembled from four existing pieces, yet they go together perfectly. I particularly enjoyed Gay but Wistful Grainger's evocation of turn-of-the-century London music halls and the succeeding Pastoral which begins innocuously enough but soon veers into stranger territory culminating in a climax which could almost have flown in from Messiaen's Turangalîla of three decades later.

Yes, Country Gardens is here, but in the revised version Grainger made in 1950 at the behest of Leopold Stokowski, making an even stranger piece out of the familiar tune.

Probably the most-recorded work here (if we discount Country Gardens) is Lincolnshire Posy, written in 1937 in response to a commission from the American Bandmaster's Association, some of whom apparently found its rhythms too tricky, resulting in an incomplete first performance. Having recently attended a rehearsal of this work I can attest to its difficulties, although they are not always exactly where one would expect them. The strange, sinuous, syncopated canon which opens the third movement, Rufford Park Poachers, sounds innocuous enough yet can cause untold performance anxiety.

The shortest piece here is Train Music an (over)ambitious work planned by the 18-year-old Grainger and inspired by a noisy and uncomfortable journey in 1900 in Italy. He scored it for a huge ensemble (including 100 strings, 8 oboes and 6 bassoons) and his aim was to portray every aspect of the journey rather than just the train itself. Even Grainger's boundless energy ultimately proved inadequate for so mammoth a task and only a fragment remains. Heard here is a fascinating glimpse of what might have been, in a reduction for standard orchestra.

Finally, and in some ways as extraordinary as anything else on this disc, are two arrangements of piano works by French composers.

Ravel, of course, was an orchestral master in his own right and orchestrated a number of his own piano pieces. Grainger's arrangement of La Vallée des cloches is beautifully sympathetic; at times reminiscent of Un barque sur l'océan or the Pavane pour une infante defunte only with rather more exotic percussion.

Speaking of which brings me to one of my favourite pieces on the disc: the arrangement of Debussy's Pagodes. There is an extant recording of Grainger (to be found on Pearl GEMMCD9957) talking about and playing this piece, a piece he evidently found endlessly fascinating. Debussy was inspired by the sound of the Javanese gamelan orchestras at the 1888 Paris exposition – as indeed, were many others; the resulting European fin-de-siecle fascination with things oriental was to lead in many directions, including Mahler's Das Lied von der Erde – and Pagodes was his (highly successful) attempt to convey their sound on the keyboard.

Grainger's arrangement, for an orchestra of what he called "tuneful percussion", is an extraordinary one: a many-layered, multi-hued treat for the ears; indeed, so skillful is his orchestration that it is easy for the listener to become convinced that this is the Javanese original of which Debussy's piano piece is a reduction.

Simon Rattle directs the Boston Symphony Orchestra in performances which are fresh and vital and well – if not spectacularly – recorded.

Although there are no major premières here, this is still a significant addition to the Grainger discography.